Couples Watch

 Nicole Richie and new beau Joel Madden, walking hand-in-hand to the patio at the Chateau Marmont hotel in West Hollywood. Richie, who's dealing with the fallout from her DUI arrest, sipped on a Coke while Madden drank juice. Before long, they were kissing passionately at their table. They also jetted to Hollywood lounge Teddy's, where the affectionate couple (Madden rested his hand on Richie's behind for a while) indulged in some cocktails and hung out with Paris Hilton. Also making the scene: Lindsay Lohan, Kate Hudson, Matthew Perry and James Franco.

 Sandra Bullock and husband Jesse James, looking "adorable together and holding hands" at L.A. eatery The Ivy. They dined on fried calamari and lime chicken.

 Naomi Watts and boyfriend Liev Schreiber, partying at Hollywood hot spot Cabana Club after the premiere of their movie The Painted Veil. "They were snuggling and holding hands in one of the cabanas," says an onlooker.

 Expectant parentsDonald Trump Jr. and wife Vanessa, going on a shopping spree to support their favorite charity, Operation Smile, at a party thrown in their honor at New York City toy store FAO Schwarz. Among their purchases: the Kate Spade Pippin Park Rocker by Maclaren ($120) and a Sleepover Pram by Silver Cross ($699.00).

 Courteney Cox and husband David Arquette, having a double date with pals Laura Dern and Ben Harper at West Hollywood eatery Il Sole. "They were really enjoying themselves," says an onlooker.

 New parentsMaggie Gyllenhaal and husband Peter Saarsgard, eating at Beverly Hills eatery Mastro's Steakhouse. Comfort food was on the agenda: steak, macaroni and cheese and sugar snap peas. "They looked very sweet together," says an onlooker. "When a diner to their right ordered shrimp on dry ice (an appetizer served in a martini glass), Maggie couldn't help but giggle as the smoke drifted toward Peter."

Karina Smirnoff and Mario Lopez

Sthanlee B Mirador / Shooting Star

 Prince William and girlfriend Kate Middleton, sampling exotic drinks with pals (including William's stepbrother Tom Parker Bowles and his wife) at hot new bar and club Mahiki in London's Mayfair neighborhood. The Polynesian-themed venue features kitschy tiki figures and 1970s-style wicker chairs, as well as music ranging from the Beach Boys to Justin Timberlake. The couple "were just chilling in the club downstairs with everyone else," a source tells PEOPLE.

 Mario Lopez, kissing and nuzzling Dancing with the Stars partner Karina Smirnoff at the Hot Hollywood party at the Sofitel Hotel in L.A. Despite their PDA (and their recent romantic Mexican getaway), Lopez insists the duo are "just friends out having a good time." Hmmm .